1. Field of the Invention
The present invention relates to an apparatus for recording and/or reproducing information.
2. Related Background Art
Information which requires recording, such as computation information, image information, etc., is on the increase at present, and a recorder with a larger capacity has increasingly been in a great demand.
Further, with the evolution of the semiconductor process technique, the miniaturization of a recorder unit is anticipated because the microprocessor has been more miniaturized with a higher computational capability. In order to satisfy such requirements, researches and experiments have been carried on with the conventional techniques using various methods, such as magnetic recording, semiconductor memory, optical disc, etc., to implement the miniaturization of the recording area (minimum recording area) for one bit, which is the minimum recording unit in these methods.
For the magnetic recording, however, at least an area of several tens of .mu.m is required as its minimum recording area for the magnetic recording head to cause changes in the magnetic flux on a magnetic recording medium. Because of this, the distance between the recording head and the recording medium is restricted, making it difficult to control the distance at less than approximately several hundred to several thousand angstroms. In the optical disc, it is also difficult to reduce the beam diameter to a dimension which is less than the optical wavelength to be applied; thus requiring several .mu.m.sup.2 as its minimum recording area.
As a means to make the minimum recording area extremely small, there has been proposed a recording and reproducing apparatus capable of providing a minimum recording area of 10 nm.sup.2, in which a fine probe, chip, etc. (hereinafter collectively referred to as a probe) for generating the tunnel current for a recording medium is arranged to write recording information by changing the work functions of the recording medium surface with the tunnel current thus generated by the probe, which passes through the recording medium, and to read information by detecting the changes in the tunnel current between the probe and medium caused by the changes in the work function as the result of writing a record on the recording medium surface. For an apparatus such as this, there are some in which a plurality of the aforesaid probes for recording and reproducing are provided for the purpose of widening the recording area. The implementation of this recording and reproducing in a wide area is attempted by transporting a recording medium against the plurality of the probes to allow the entire probes to scan the recording medium surface at one time and perform the recording or reproducing by the tunnel current at that juncture.
However, in an apparatus for recording and reproducing such as this, the recording medium is transported at the time of scanning for recording or reproducing by each of the probes, and the respective probes are fixedly positioned with each other, or movably positioned only in the direction perpendicular to the medium, which each of them face, to adjust the space between the probe and medium. Therefore, in a case when each of the probes is caused to scan for recording along the specified path on the recording medium surface or to scan for reproducing the recorded information at each location sequentially, it is impossible to control each scanning by the respective probes. Consequently, there is a possibility that a recording or reproducing error occurs for a probe or probes because one or plural ones of the entire probes cannot scan along the specified path and information sequence even if the entire scanning is precisely controlled. Particularly, in a recording and reproducing apparatus using the tunnel current, there is a possibility that the recording and reproducing become impossible because its minimum recording area is so narrow that even if the thermal expansion of the recording medium and changes with the time elapsed are small, the resultant changes in the recording position produce a great affect, and if any one of the probes is adjusted to scan along the specified path and information sequence, the other probes are caused to be positioned apart entirely from the specified path and information sequence.